The present invention relates generally to appliance devices, and more particular, to appliance devices having electrical control circuits.
Appliance devices such as dishwashers, clothing washing machines, dryers, ovens, refrigerators and the like often include electrical control circuits. Such control circuits receive input from the user and control the operation of the appliance device based on the received input. In many cases, the overall operation of the appliance is predefined as a general matter and the user input merely modifies the predefined operation in some way.
For example, the operation of a dishwasher typically involves the processes of filling, washing, draining and rinsing. Such operations involve, among other things, the control of water valves, detergent valves and motor relays. The general sequence of such operations is generally predefined. However, user input may be used to alter the sequence, or to define certain parameters of the sequence. For example, the user input may define whether the wash cycle is normal, light, or heavy. Although the general sequence does not necessarily change dependent upon wash cycle selection, the length of certain processes within the sequence does change.
A typical user input interface for a dishwasher includes a rotary knob and a plurality of pushbutton switches. The rotary knob is attached to a cam that controls the sequence of operations within the dishwasher. The cam has a number of followers that trigger the operation of the various dishwasher components. The cam followers are positioned to cause various operations to be executed in a xe2x80x9cprogrammedxe2x80x9d sequence. The user selects a particular cycle by rotating the knob to particular position associated with the selected cycle. Upon actuation, the cam begins to rotate automatically started from the user selected position, performing each operation as defined on the cam xe2x80x9cprogramxe2x80x9d from the user-selected point forward. The pushbutton switches are used to activate/deactivate various options that are not available through the cam program. For example, pushbutton switches may be used to selectively activate a heated dry cycle, a delayed start, or a high temperature wash.
More recently, electronic controllers, for example, microprocessors and microcontrollers, have replaced the rotary cam control device. Because the rotary cam no longer controls the operation of the various dishwasher electromechanical devices, a rotary knob is no longer the inherent choice for a user input device. As a result, user inputs to such electronic controllers have been implemented as exclusively pushbutton switches, membrane keypad switches, or the like.
One disadvantage of the elimination of the traditional rotary knob interface is the potential for lack of widespread consumer acceptance. Traditional rotary knobs provide a familiar tactile and visual feedback to consumers, and operate in a manner instinctively known to consumers from years of use. Accordingly, it can be advantageous to employ a traditionally-styled interface, even in appliances that do not employ rotary cam controls.
The drawback to the use of the traditional interface of rotary switches and the accompanying pushbuttons for the optional features is the cost associated with the interface. Specifically, inclusion of multiple pushbuttons and a separate rotary knob requires adds significant part and manufacturing costs. There is a need, therefore, for an improved appliance control device that combines low cost with convenience, consumer familiarity, and intuitive operation.
The present invention addresses the above needs, as well as others, by providing an appliance control apparatus that incorporates a rotating position switch and a selector switch that are used in combination to enter user selections. The use of the rotating position switch and the selector switch retains the advantages of employing a rotary switch while eliminating or at least reducing the need for multiple other pushbutton switches.
In accordance with an exemplary embodiment of the present invention, the rotating position switch has a first position associated with a first appliance function and a second position associated with a second appliance function. The second appliance function modifies the first appliance function. The selector switch has an actuated state configured to generate a signal representative of a selection of the first appliance function when the rotating position switch is in the first position. The actuated state is further configured to generate a signal representative of a selection of the second appliance function when the rotating position switch is in the second position.
In such an embodiment, the number of pushbutton or membrane switches may be reduced over prior art designs because the rotating switch mechanism is used to identify two different appliance functions. In other words, instead of using a plurality of pushbutton or membrane switches to identify a second appliance function, as was done in the prior art, the rotating switch is used again for that purpose. As a result, the mechanical complexity associated with using a large number of pushbutton or membrane switches may be reduced.
Another embodiment of the present invention is a method of operating an appliance based on first and second user selections. The method includes the steps of adjusting a rotating position switch to a first position representative of a first user selection and actuating a selector switch to provide a first signal representative of the first user selection to a control circuit. The method further includes adjusting the rotating position switch to a second position representative of a second user selection and actuating the selector switch to provide a second signal representative of the second user selection to the control circuit. The method also includes performing the operation based on the first signal and the second signal.
The embodiment described above provides an intuitive method for controlling an appliance that does not require a large quantity of pushbutton switches.
The above described features and advantages, as well as others, will become more readily apparent to those of ordinary skill in the art by reference to the following detailed description and accompanying drawings.